fix(bigquery-jdbc): add proper version to BigQueryDriver

[logachev]

Update BigQueryDriver getMinorVersion/getMajorVersion to return proper value

[gemini-code-assist]

Code Review

This pull request refactors the JDBC driver version loading and parsing logic by moving it from BigQueryDatabaseMetaData into a new utility class, BigQueryJdbcVersionUtility, which is then used by both BigQueryDatabaseMetaData and BigQueryDriver. A critical review comment points out a concurrency race condition in the lazy initialization of the utility class, which could lead to threads reading uninitialized major or minor versions. Additionally, the comment highlights a bug where single-part version strings would prevent the major version from being set. The reviewer suggests resolving these issues by using a thread-safe static initializer block to load the properties.

[gemini-code-assist]

Concurrency Race Condition & Robustness Issue

There is a race condition in the lazy initialization logic of ensureLoaded(). If multiple threads call ensureLoaded() concurrently, one thread (Thread A) can set parsedDriverVersion but get context-switched before setting parsedDriverMajorVersion or parsedDriverMinorVersion. If another thread (Thread B) then calls getDriverMajorVersion(), it will see parsedDriverVersion.get() != null as true, skip loading, and return 0 (since parsedDriverMajorVersion is still null).

Additionally, if the version string has only one part (e.g., "1"), parts.length < 2 causes an early return, meaning the major version is never set and defaults to 0.

Solution

Since this is a utility class loading static classpath resources, using a static initializer block is the most standard, robust, and thread-safe approach. It completely eliminates the race condition, removes the need for AtomicReferences and ensureLoaded() overhead, and makes the fields private static final.

package com.google.cloud.bigquery.jdbc.utils;

import com.google.cloud.bigquery.jdbc.BigQueryJdbcCustomLogger;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

/** Utility class to load and parse the JDBC driver version from dependencies.properties. */
public final class BigQueryJdbcVersionUtility {

  private static final BigQueryJdbcCustomLogger LOG =
      new BigQueryJdbcCustomLogger(BigQueryJdbcVersionUtility.class.getName());

  private static final String driverVersion;
  private static final int driverMajorVersion;
  private static final int driverMinorVersion;

  static {
    String version = "0.0.0";
    int major = 0;
    int minor = 0;
    try (InputStream input =
        BigQueryJdbcVersionUtility.class.getResourceAsStream(
            "/com/google/cloud/bigquery/jdbc/dependencies.properties")) {
      if (input == null) {
        String errorMessage =
            "Could not find dependencies.properties. Driver version information is unavailable.";
        IllegalStateException ex = new IllegalStateException(errorMessage);
        LOG.severe(errorMessage, ex);
        throw ex;
      }
      Properties props = new Properties();
      props.load(input);
      String versionString = props.getProperty("version.jdbc");
      if (versionString == null || versionString.trim().isEmpty()) {
        String errorMessage =
            "The property version.jdbc not found or empty in dependencies.properties.";
        IllegalStateException ex = new IllegalStateException(errorMessage);
        LOG.severe(errorMessage, ex);
        throw ex;
      }
      version = versionString.trim();
      String[] parts = version.split("\\.");
      if (parts.length > 0) {
        major = Integer.parseInt(parts[0]);
      }
      if (parts.length > 1) {
        String minorPart = parts[1];
        String numericMinor = minorPart.replaceAll("[^0-9].*", "");
        if (!numericMinor.isEmpty()) {
          minor = Integer.parseInt(numericMinor);
        }
      }
    } catch (IOException | NumberFormatException e) {
      String errorMessage =
          "Error reading dependencies.properties. Driver version information is"
              + " unavailable. Error: "
              + e.getMessage();
      IllegalStateException ex = new IllegalStateException(errorMessage, e);
      LOG.severe(errorMessage, ex);
      throw ex;
    }
    driverVersion = version;
    driverMajorVersion = major;
    driverMinorVersion = minor;
  }

  private BigQueryJdbcVersionUtility() {
    // Utility class, static methods only.
  }

  /**
   * Gets the full driver version string.
   *
   * @return the driver version string, e.g., "1.0.0-SNAPSHOT"
   */
  public static String getDriverVersion() {
    return driverVersion;
  }

  /**
   * Gets the driver major version.
   *
   * @return the major version number
   */
  public static int getDriverMajorVersion() {
    return driverMajorVersion;
  }

  /**
   * Gets the driver minor version.
   *
   * @return the minor version number
   */
  public static int getDriverMinorVersion() {
    return driverMinorVersion;
  }
}

[keshavdandeva]

Agree with gemini, we should address concurrency issue here

[keshavdandeva]

So, this and the minorVersion function with this new impl could throw IllegalStateException for BigQueryDriver.getMajorVersion() and getMinorVersion(), right?
I think we need to confirm JDBC spec if that's okay or should it throw SQL exception or should it default to something and not throw error at all

[keshavdandeva]

same as above

[keshavdandeva]

Agree with gemini, we should address concurrency issue here

[keshavdandeva]

Can we also update the README in this PR for the maven link